Air Safety

Contriving to get the Friday afternoon off from their respective places of work, they all meet at the flying school at Moorabbin soon after 1400 hours. After Rick has pre flighted the Cherokee, he and Ken leave their two passengers to stow the luggage in the aircraft while they go off to Briefing to get the area forecast and to flight plan as far as Mt Gambier. Overnighting at Mt Gambier will place them well for an early Adelaide arrival on Saturday, thus making the most of their weekend.

The afternoon forecast is for “Wing Commander’s weather” with a south easterly following wind and only broken cloud above about 5000 feet (1325m). At the end of a pleasant, uneventful flight during which Rick handles the aeroplane while Ken navigates and operates the radio, they touch down smoothly on Mt Gambier’s Runway 11 just on 1630 hours CST. They order a taxi and while it is coming from town, Rick takes the precaution of topping the Cherokee up with fuel, even though he estimates they have ample for the remaining leg to Adelaide without infringing the statutory reserve of 45 minutes.

Booking into the Blue Lake Hotel, they order an early breakfast, pass an agreeable evening playing pool with a couple of acquaintances from the local aero club, and sleep soundly. In high spirits they all take a taxi back to the airfield in the morning, and by 0730 hours CST, the two pilots are preparing their flight plan at the Mt Gambier Flight Service office.

The forecast for the leg to Adelaide is much the same as the day before – mainly fine with broken cloud only at higher levels. But under the influence of the easterly stream weather, some morning drizzle is expected on the eastern slopes of the Mt Lofty Ranges, with cloud enveloping the higher peaks, particularly during the earlier part of the day. But as the pilots plan to cruise at only 1500 feet (460m) to have a good view of the Coorong, the Murray River mouth, and Lake Alexandrina enroute, the weather does not seem to pose any difficulty. At 0755 hours CST, with Rick again in the left hand seat and Ken beside him, the engine is started and the Cherokee taxies out for takeoff. A few minutes later, after a normal runup at the threshold of Runway 22, Rick takes off and turns left to set course. At 0805 Ken passes their departure call to Mt Gambier Flight Service, giving an ETA of 0955 hours CST for Adelaide. At 0820 hours he reports they are over Millicent, cruising below 5000 feet. Navigating conscientiously and accurately, he reports again abeam Bordertown, then over Meningie at 0922, he calls Adelaide Control in his best R/T phraseology, requesting a clearance into controlled airspace. The controller comes back promptly, clearing the Cherokee to enter the Adelaide Control Area on track, “not above 3000”, and instructs them to report again at Mt Bold Reservoir, a well defined reporting point in the Adelaide hills, only 14 nautical miles (26km) south east of Adelaide airport.

With the Cherokee approaching the Mt Lofty Ranges from the south east over Lake Alexandrina, let’s now try to put ourselves in its occupant’s shoes to replay the final tragic 40 minutes of the flight. We do so not to dwell on the pathos of the events that follow – but that we might learn from the object lessons they provide.

It is now evident to the four friends that the area forecast was right: there is cloud- and probably rain too – on the hills ahead. But it is obviously localised, and away from the ranges the weather looks as good as ever.

To Darryl and Tom in the back seat, blissfully ignorant of the gulf that exists between VFR and IFR procedures, it means little more than having the excellent views they have been enjoying restricted for a few minutes. They sit back, content to leave the pilots to their task, and look forward to landing in Adelaide very soon.

Ken, in the right hand seat with the charts and flightplan on his knee, is a little more anxious. But he has confidence in Rick after all his friend has been flying for three years now and no doubt knows what he is doing. Anyway, there is plenty of time and airspace to allow a diversion if it becomes necessary. But just in case they have to request a change in clearance, he takes the microphone from its hook and holds it in his hands.

Rick, outwardly exuding confidence, but feeling a little daunted inwardly, maintains heading, his mind working overtime. He is not accustomed to flying in primary control areas and is in awe of air traffic controllers. Moreover, a clearance has already been given to them. Because he does not want to make a fool of himself or reveal his lack of experience, Rick decides it’s best to do nothing at this stage. The problem ahead may turn out to not be a problem at all. He’ll just wait and see what eventuates when they get closer.

Approaching Strathalbyn with the rising ground only a few miles ahead, he is forced to descend a little from 1500 feet (460m) to remain below the thickening layer of cumulus cloud that is sitting on the ranges. But there is no question of not being able to continue. Admittedly, the overcast is forcing them to fly a bit lower than he would in better conditions, but they are not dangerously low.

Alongside him Ken says nothing, though he is doing plenty of looking around. But Rick is the pilot-in-command; he must defer to his greater experience and sounder judgement. And he doesn’t want to say anything that might alarm Darryl and Tom. They are clearly enjoying the whole experience and it would be wrong to spoil their trip. In any case, in a little over 10 minutes they should be through this weather and letting down into Adelaide in unlimited visibility.

Conditions worsen as the timbered hills rise beneath them. A mile to starboard, a massive ridge rears into the base of the overcast itself. By the time they have passed the township of Medows, they are skimming the tops of a pine forest. But suddenly the forest falls away and there in the wide valley in front of them is the magnificent Mt Bold Reservoir, its upper reaches stretching away to the north.

A little tensely, Ken puts the microphone to his mouth and reports their position. Adelaide Control comes back with a cheerful instruction to make a VFR approach and to call the Tower at five miles. The pilots grin with relief at each other. Only a little more of this and they’ll be there! But beyond the reservoir, the ground rises quickly once more and soon they are skimming the hills again, now thickly covered in eucalypt forest. And as well as the lowering overcast, they are having to contend with patches of rain which is making forward visibility more difficult.

The passengers in the back have fallen ominously silent- the nearness of the tree tops flashing past below the aircraft and the pervading wet gloom is unsettling. Their ebullient mood of a few minutes ago has gone.

Ken looks across at Rick questioningly. Does Rick want him to call Control to say they are turning back? But Rick’s eyes are fixed ahead, concentrating hard. Occasionally now they are flying through patches of cloud hanging from the base of the overcast. Fortunately they are small, and the awesome feeling of being completely in cloud is only momentary. Yet it’s hard to avoid them with the visibility so poor in the rain- Ken finds they are sometimes into the patches before he realises they are there. Hoping fervently that Rick does know what he is doing, he grits his teeth to subdue his fear. The western edge of the ranges can’t be much further – please let them be through all this soon! Ahead of them another timbered ridge emerges out of the misty rain, seemingly rising to their own height. Seeing it, Rick instinctively eases back the control wheel slightly to lift the aircraft over it.

Suddenly it happens – they are enveloped in cloud and instantly the world beyond the cabin windows is reduce to nothing more than an opaque damp greyness. But this time it is no mere patch – they are staying in it! Rick’s grip on the control wheel tenses. His knuckles gleam white as he fights to suppress the panic rising within him. He was always certain he wouldn’t let himself get caught in cloud, but now it’s happened! Yet if he can just keep the aircraft level and heading in the right direction, they might just come out of it. The tension in the Cherokee’s cabin is palpable as they fly on, no one speaking. There seems to be no end to the cloud. Rick strains through the windscreen, desperately trying to make out the slightest glimpse of the real world beyond the meaningless grey void into which they have been plunged. But there is nothing. . .

The cloud is only a little turbulent. But without visual reference it is sufficient to upset all sense of direction. What is the aircraft doing? It is hard to tell if it is flying straight and level now. Sometimes it feels as if it is turning, sometimes banking, sometimes even diving or climbing slightly. From time to time Rick flicks his vision from the emptiness beyond the windscreen into which he is gazing to the instrument panel. They are only brief glances, but nothing looks particularly abnormal. Untrained in instrument flying, he dares not risk missing a precious outside visual cue while preoccupied with interpreting the panel indications.

Suddenly, out of the corner of his eye, he catches a fleeting glimpse of something shadowy, hurtling towards them at frightening speed. Amillisecond later the starboard wing lops off the uppermost branches of a gum tree with a heart-stopping screech of tortured metal. There is a frightened shout from the rear seat and the Cherokee lurches drunkenly. Somehow it recovers and they fly on, the leading edge of the wing visibly damaged.

It is too much for Ken and he cracks. His eyes wild now with terror, he suddenly turns and screams at Rick: “Turn back you bloody idiot – you’ll get us all killed!” Rick needs no second bidding. But first he must master the controls. Since entering cloud the Cherokee has been flying him, not the other way round. His face ashen and his emotions barely under control, he desperately tries to force himself to concentrate on the artificial horizon and the directional gyro. It is almost impossible; all his instincts tell him he must keep looking outside for reference.

The aeroplane seems to still be flying more or less straight and level. Very tentatively he applies a little right aileron and rudder to begin a turn back on to a reciprocal heading. He feels the Cherokee respond, but then the turn seems to stop. It certainly doesn’t feel as though it is turning now; no that can’t be so the needle on turn and bank indicator is over to the right. He applies a little more aileron and rudder, just to be sure. . .

Look out now-that ball isn’t in the centre any more – the aircraft must be slipping in! Quickly, use the rudder to correct. But wait-isn’t it skidding instead? Keep calm now – which way is that ball indicating? Hey, what’s happening to the airspeed? The nose must have dropped! Ease the wheel back a bit – ah, that’s better. Or is it now? Why is that “g” coming on? And what’s happened to the turn needle – it’s hard over against the stop! The turn must have tightened – put the wheel forward again before we stall! No not that much-now we’re diving-and the “g” is getting worse-hear the engine screaming! Look out, the altimeter is unwinding like mad! Try not to panic – do something quickly. . .

Several minutes later, when the Tower Controller has heard nothing from the Cherokee, both he and the Approach Controller begin calling it on their respective frequencies. There is no reply. They are still trying to re-establish radio contact when the Senior Operations Controller receives a grim message from the police – a light aircraft is reported to have crashed to destruction in the Coromandel Valley in the Mt Lofty Ranges where the terrain falls abruptly to the Adelaide coastal plain.

The force of impact was tremendous, forcing the propeller and engine nearly a metre into the ground and completely demolishing the aircraft’s structure. The investigators determine that, at the moment of impact, the engine was under at least cruising power and the aircraft steeply banked to starboard. Watches they recover from the mutilated bodies in the wreckage have stopped at 1000 hours.

Enquiries establish that the weather in the area at the time of the accident was showery, with four octas of stratus cloud at 1000 feet (305m), and an overcast layer of cumulus at 2000 feet (610m). Clear of the cloud and rain, visibility was good.

A farmer, working on his valley property just to the north of the Mt Bold Reservoir, tells the investigators he saw the Cherokee flying low in the general direction of Adelaide shortly before 10am. Though the ridges were clear of cloud, the sky was overcast and the Cherokee was passing through patches of rain. Its height would have been only about 100 feet (31m) above over the surrounding ridge tops.

On the higher terrain in the vicinity of the accident four nautical miles (7km) further north, the weather on the ground was foggy and visibility poor. A number of people living in this area tell the investigators they could not sight the Cherokee at any time because of the conditions, but all heard it flying low shortly before the crash.

Two workmen constructing a shed only 300 metres away from the accident site, heard the aircraft pass over them. Even though it was obviously very low, it was invisible in the fog like cloud. Soon afterwards there was a sound of breaking timber. The aircraft continued on in the general direction of Adelaide until it was almost out of earshot, then seemed to be returning in their direction. As it neared them again, the engine note progressively rose in pitch as the aircraft apparently circled. The engine was screaming by the time it dived into the ground. An abrupt silence followed the unmistakeable thud of impact. The workmen’s evidence leads the investigators to locate a tall gum tree whose upper branches have been struck by the Cherokee’s starboard wing. It is evident that, following this impact, the Cherokee maintained its heading for about one nautical mile (2km) before beginning the turn back towards the accident site.

Reconstructing the final minutes of the ill fated flight, the investigators conclude that visual conditions on the direct Meningie/Adelaide track deteriorated rapidly shortly after the crew reported their position at the Mt Bold Reservoir. Already flying dangerously low in an effort to maintain visual contact, the Cherokee would have been progressively “squeezed” into a diminishing gap by the overlying cloud and the increasing height of the ranges until it was caught in cloud completely. For the pilots in this appalling situation, with no instrument flying experience to fall back on, there could only be one result-disorientation and loss of control.

At no stage did the Cherokee’s crew give any indication that they were having difficulty in maintaining VFR flight on the direct track to Adelaide. The Approach Controller had no way of knowing what the precise weather conditions were in the Mt Bold area at the time. Had he been informed, he could have either offered the aircraft an alternative route clearance, or approved one which the pilots proposed.

A clearance from Air Traffic Control can never relieve a pilot-in-command of his responsibility for the ultimate safety of his aircraft. It is especially tragic that although VFR flight was not possible on the direct Meningie/Adelaide route at the time of the accident, it could easily have been maintained only a few nautical miles further to the south where the terrain is lower.

This unhappy but salutary story is based on an actual accident. Only inconsequential details have been changed to protect the identity of the victims and their relatives.